JP2016518528A - Electrical terminal element - Google Patents

Abstract

The present invention relates to an electrical terminal element comprising a connection segment formed from a copper sheet, comprising at least two layers and comprising a coating comprising tin.

Description

  The invention relates to an electrical terminal element comprising a coating comprising at least two layers and comprising tin, as well as a method for producing such a terminal element.

  From the perspective of climate protection, reducing emissions of greenhouse gases such as carbon dioxide is particularly important. Thus, the automotive industry is striving to develop automobiles, which are relatively low fuel consumption, thereby reducing carbon dioxide emissions and contributing to climate protection.

  One approach to reducing fuel consumption and thus carbon dioxide emissions is based on reducing the weight of the vehicle. In order to achieve weight control, the replacement of relatively heavy materials with lighter materials and the search for the possibility that automotive parts can be formed from lighter materials has been enhanced.

  According to this concept, there is also an effort to reduce the weight of automobile wiring by replacing copper, which is typically used in cables as a conductor material, with alternative lightweight materials. A possible conductor material is aluminum, which is in principle suitable for replacing conductors, has a low density as a light metal, and thus is itself lightweight.

  However, when aluminum is used as the conductor in combination with electrical terminal elements, which are typically made of copper, there is a corrosive action at the contact between copper and aluminum due to the presence of electrolytes such as salt water and oxygen in the air. There are disadvantages that arise. These corrosive effects occur especially in the case of direct contact between copper and aluminum, because of the electrochemical series, the difference in standard potential (normal potential) between aluminum and copper, and thus high propulsion for the corrosion reaction It is necessary to consider power. Through electrolytic corrosion, the amount of aluminum as a less precious metal is reduced compared to copper, which significantly reduces the conductivity at the contact between the conductor material and the terminal element. Thus, there is a need for reliable anticorrosion when using aluminum conductor materials in combination with copper electrical terminal elements.

  The present invention is therefore based on the object of providing an electrical terminal element, the terminal of which can be used in combination with an aluminium-containing conductor material, providing reliable protection against corrosion.

  This object is solved by an electrical terminal element having the features of claim 1.

  The terminal element according to the invention comprises a connecting segment with a coating formed from a copper sheet and comprising a first layer comprising tin. The coating further comprises a second layer disposed between the first layer and the copper sheet. The second layer comprises at least a metal or at least an alloy selected from the group comprising a copper-containing alloy, nickel, a nickel-containing alloy, palladium, a palladium-containing alloy, and combinations of the foregoing metals and alloys. Yes.

  The present invention is based on the general idea that the electrochemical potential of the connecting segment approaches the potential of aluminum, which, according to the electrochemical series, provides contact with the aluminum-containing conductor material It is further reduced by coating the connection element of the copper sheet of the terminal element. In this way, the potential difference between copper and aluminum is at least approximately complemented, whereby the driving force for corrosion is reduced and is no longer in a critical range. This anticorrosion has been achieved by coating with elements containing tin, especially between copper and aluminum in the electrochemical series.

  The anticorrosion function is achieved in particular by a first layer containing tin, which is between copper and aluminum in the electrochemical series.

  In contrast, the second layer provides a barrier function. By arranging the second layer between the first layer containing tin and the copper sheet of the connection segment, the exchange of metal atoms by diffusion between the first layer containing tin and the copper sheet of the connection segment can be achieved. Is prevented. Without this barrier layer, there is a risk of tin diffusion from the first layer to the copper sheet over the life of the vehicle and the formation of hollow spaces or holes in the first layer. The formation of such hollow spaces and / or cracks promotes penetration of electrolyte into the layer system and promotes unwanted corrosion. In order to avoid this, the second layer is arranged between the tin-containing first layer and the copper sheet of the connecting segment, this layer comprising at least a metal or at least an alloy, which comprises a copper-containing alloy, nickel Selected from the group comprising nickel-containing alloys, palladium, palladium-containing alloys, and combinations of the aforementioned metals and alloys.

  All that has been considered is that the terminal element of the present invention has excellent protection against corrosion at the contacts between the terminal element and the aluminum-containing conductor material, and at the same time is minimized by the optimized coating conductivity. And ensuring optimum permanent contact with the conductor material.

  The terminal element according to the invention is suitable for contact with wires that contain aluminum as a whole. More preferably, the terminal element can be used in the construction of an automobile, which in this way is an aluminum containing wire is used instead of a copper containing wire, thereby This is because weight savings and therefore fuel savings and reduced carbon dioxide emissions can be achieved.

  Advantageous embodiments of the invention are disclosed in the dependent claims, the description and the figures.

  The connection segment of the electrical terminal element is an area provided for receiving the conductor material of a wire such as a cable. This can be performed, for example, by a crimp connection with a conductor material.

  At least the connection segment of the electrical terminal element is formed from a copper sheet. However, other parts, and particularly finished terminal elements, may be formed from a copper sheet. For example, the terminal element can be composed of a punch / bend.

  In each case, a coating is formed on the connecting segment of the electrical terminal element in order to be able to act as an anticorrosion. However, the coating may be present in other areas of the terminal element, and in principle it is conceivable that the coating completely covers the surface of the terminal element. However, it is preferred that the coating is limited only to the connection segment of the terminal element, and the remaining area of the terminal element, in particular the area intended to contact the mating terminal element, e.g. plug part or socket part, It is preferred to have no coating and to ensure an optimal electrical connection between the terminal elements.

  Advantageous embodiments of the invention are described below.

  Satisfactory results from the point of view of the barrier function indicate that the second layer preferably has a thickness of 0.1 to 5 μm, more preferably 0.5 to 5 μm, more preferably 0.5 to 5 μm. The case of having a thickness of ˜3 μm, the case of having a thickness of 0.7 to 2.5 μm, and the case of having a thickness of 0.8 to 2.2 μm is most preferred.

  Further, the second layer can include a copper-containing alloy. In particular, the second layer may consist of a copper-containing alloy.

  For example, the copper-containing alloy is about 35-97 wt% copper, preferably 40-90 wt% copper, more preferably 45-80 wt% copper, most preferably 50- It contains 65% by weight of copper and has achieved good results from the viewpoint of barrier function.

  Furthermore, the copper-containing alloy may contain a metal between copper and aluminum in the electrochemical series. In this way, the second layer reduces the potential difference between the aluminum potential and the terminal element copper sheet and the aluminum-containing conductor material, providing a contribution to reducing the driving force associated with the corrosion reaction. ing. For example, the copper-containing alloy may contain tin and / or zinc. Thus, bronze alloys or brass alloys can be used, for example as copper-containing alloys. Optionally, the bronze alloy may additionally contain zinc additionally, whereas, conversely, the brass alloy may optionally contain tin.

  To form an effective diffusion barrier and to achieve good corrosion protection, the second layer can include tin and zinc, or a copper-containing alloy that includes one of them.

  Preferably, the copper, tin, and zinc-containing alloys are more preferably 35-75 wt% copper, 15-45 wt% tin, and 5-50 wt% zinc, respectively, for a 100 wt% copper-containing alloy. 40-70 wt% copper, 20-40 wt% tin, and 10-30 wt% zinc, even more preferably 45-65 wt% copper, 25-35 wt% tin, and 10-30 It may contain wt% zinc, most preferably 48-60 wt% copper, 27-333 wt% tin, and 12-20 wt% zinc. The sum of copper, tin and zinc is preferably at least 90% by weight for a 100% by weight copper-containing alloy. The balance up to 100% by weight of the copper-containing alloy is an alloy component that can be commonly used for copper-containing alloys, such as nickel, palladium, phosphorus, aluminum, iron, cobalt, manganese, tungsten, gold, silver, And / or lead and / or inevitable impurities.

  According to a further embodiment, the second layer may comprise or consist of one of the copper, tin and zinc containing alloys, preferably with respect to 100% by weight of the copper containing alloy, preferably between 35 and 75 respectively. Wt% copper, 15-45 wt% tin, and 5-50 wt% zinc, more preferably 40-70 wt% copper, 20-40 wt% tin, and 10-30 wt% zinc, Even more preferably 45-65 wt% copper, 25-35 wt% tin, and 10-30 wt% zinc, most preferably 48-60 wt% copper, 27-33 wt% tin, and 10 It may contain ˜30 wt% zinc, and the sum of copper, tin and zinc is preferably at least 95 wt% for a 100 wt% copper-containing alloy. The balance up to 100% by weight of the copper-containing alloy is an alloy component that can be commonly used in copper-containing alloys, which can be, for example, the elements and / or inevitable impurities listed in the previous paragraph.

  According to a further embodiment, the second layer may comprise or consist of one of the copper, tin and zinc containing alloys, preferably with respect to 100% by weight of the copper containing alloy, preferably between 35 and 75 respectively. Wt% copper, 15-45 wt% tin, and 5-50 wt% zinc, more preferably 40-70 wt% copper, 20-40 wt% tin, and 10-30 wt% zinc, Even more preferably 45-65 wt% copper, 25-35 wt% tin, and 10-30 wt% zinc, most preferably 48-60 wt% copper, 27-33% wt tin, and 12 It may contain -20% by weight zinc, and the sum of copper, tin and zinc is preferably at least 98% by weight for a 100% by weight copper-containing alloy. The balance up to 100% by weight of the copper-containing alloy is an alloying component that can be commonly used in copper-containing alloys, which can be elements and / or unavoidable impurities listed in both previous paragraphs.

  An effective diffusion barrier and good corrosion protection is also achieved when the second layer comprises a copper and zinc containing alloy or consists of one such alloy.

  Preferably, such copper and zinc-containing alloys are 40 to 80 weight percent copper and 20 to 60 weight percent zinc, more preferably 50 to 75 weight percent copper and 25 weight percent with respect to 100 weight percent copper-containing alloy. ~ 50 wt% zinc, even more preferably 55 to 70 wt% copper and 30 to 45 wt% zinc, most preferably 57 to 68 wt% copper and 32 to 43 wt% zinc. Thereby, the sum of copper and zinc is preferably at least 90% by weight for a 100% by weight copper-containing alloy. The balance up to 100% by weight of the copper-containing alloy is an alloy component that can be commonly used for copper-containing alloys, such as nickel, palladium, phosphorus, aluminum, iron, cobalt, manganese, tungsten, gold, silver, And / or lead and / or inevitable impurities.

  According to a further embodiment, the second layer may comprise copper and a zinc-containing alloy, preferably 40 to 80% by weight copper and 20 to 60% by weight zinc, with respect to 100% by weight copper-containing alloy, More preferably 50-75% copper and 25-50% zinc, even more preferably 55-70% copper and 30-45% zinc, most preferably 57-68% copper and 32 Contains ˜43 wt% zinc and the sum of copper and zinc is at least 95 wt% for a 100 wt% copper-containing alloy. The balance up to 100% by weight of the copper-containing alloy is an alloying component that can be commonly used for copper-containing alloys, which can be, for example, the elements listed in both previous paragraphs and / or unavoidable impurities.

  According to a still further embodiment, the second layer may comprise copper and a zinc-containing alloy, preferably 40 to 80% by weight copper and 20 to 60% by weight zinc with respect to 100% by weight copper-containing alloy. More preferably 50-75% copper and 25-50% zinc, even more preferably 55-70% copper and 30-45% zinc, most preferably 57-68% copper and It contains 32 to 43% by weight of zinc and the sum of copper and zinc is preferably at least 98% by weight for a 100% by weight copper-containing alloy. The balance up to 100% by weight of the copper-containing alloy is an alloy component that can be commonly used in copper-containing alloys, and in particular may be the elements and / or inevitable impurities listed in the previous two paragraphs.

  According to an alternative embodiment, the second layer may comprise nickel or a nickel-containing alloy, particularly preferably made of nickel or a nickel-containing alloy. When the second layer comprises nickel or a nickel-containing alloy or consists of a nickel-containing alloy, the nickel component is preferably at least 80 wt.%, More preferably at least 90 wt. More preferably at least 95% by weight and most preferably at least 98% by weight. The balance up to 100% by weight of nickel or up to 100% by weight of nickel-containing alloys are alloy components that can be commonly used for nickel-containing alloys, such as copper, palladium, platinum, aluminum, cobalt, manganese, Silicon, chromium, iron, zinc, molybdenum, tungsten, magnesium, and / or titanium.

  Further alternatively, the second layer may comprise palladium or a palladium-containing alloy, or in particular may consist of one of them, and for a 100% by weight palladium-containing alloy, the palladium component is preferably at least 80% by weight. % Palladium, more preferably at least 90% by weight palladium, more preferably at least 95% by weight palladium, and most preferably at least 98% by weight palladium. The balance up to 100% by weight of palladium, or up to 100% by weight of palladium-containing alloys, is an alloy component that can be commonly used for palladium-containing alloys, such as copper, nickel, platinum, silver, and / or gold. And / or like inevitable impurities.

  According to a further embodiment, the first layer of coating is the outer layer and is intended for direct contact with the conductor material. Furthermore, the first layer is preferably immediately adjacent to the second layer, i.e. the first layer is preferably directly above the second layer.

  According to yet another embodiment, good protection against corrosion is achieved especially when the first layer comprises at least 60% by weight of tin with respect to the 100% by weight of the first layer. Preferably, for a 100 wt% first layer, the first layer contains at least 70 wt% tin, more preferably at least 80 wt% tin, most preferably 90 wt% tin. In particular, the first layer is a high purity tin layer, for example comprising at least 95% by weight tin, or at least 98% by weight tin.

  In addition, the first layer may contain zinc, and the addition of zinc may bring the potential of the first layer closer to that of the aluminum-containing conductor material, according to the electrochemical series, zinc is a lower standard than tin. Although it has a potential, it has a higher standard potential than aluminum and can therefore reduce the potential difference as a driving force for corrosion. For example, for a 100 wt% first layer, the first layer is 0-40 wt% zinc, preferably 2-30 wt% zinc, more preferably 5-25 wt% zinc, most preferably 10 It may contain up to 20% by weight of zinc. When the first layer contains both tin and zinc, for a 100 wt% second layer, the sum of tin and zinc is preferably 90 wt%, more preferably 95 wt%, most preferably 98 wt%. is there. The balance up to 100% by weight of the second layer can be common components used in tin and / or zinc alloys and / or inevitable impurities.

  Also, in order to achieve effective anti-corrosion for the life normally expected in automobile equipment, the second layer is particularly 0.1-5 μm thick, more preferably 0.5-5 μm thick, more suitable For example, the first layer preferably has a thickness of 0.5 to 3 μm, even more preferably 0.7 to 2.5 μm, most preferably 0.8 to 2.2 μm. The thickness is ˜15 μm, more preferably 2 to 10 μm, even more preferably 3 to 7 μm, and most preferably 4 to 6 μm.

  According to yet another embodiment, the coating may further comprise a third layer disposed between the second layer and the copper sheet and comprising tin. Such a third layer is present when a copper sheet is used as the starting material and a tin layer formed by hot tin plating is provided to produce an electrical terminal element. If a third layer is present, for example for a hot-tin plated copper sheet, that layer is considered as part of the coating and not as part of the copper sheet.

  Where there is a third layer, with respect to 100% by weight of the third layer, that layer is preferably at least 80% by weight tin, more preferably at least 90% by weight tin, even more preferably at least 95% by weight tin, most Preferably it contains at least 98% by weight of tin. Most preferably, the third layer consists of tin.

  The thickness of the third layer may be in the range of 0.01-5 μm, preferably 0.5-3.5 μm, more preferably 1-2 μm.

  According to a further preferred embodiment, the third layer is directly adjacent to the second layer and / or to the copper sheet of the terminal element. If the third layer is not provided, the second layer may be formed directly on the copper sheet of the terminal element and adjacent to the copper sheet.

  Furthermore, the coating may comprise a fourth layer disposed on the side of the second layer and the first layer opposite the copper sheet and comprising zinc. Such a fourth layer can be formed as an outer layer. In addition, the fourth layer may be directly adjacent to the first layer. Such a structure of the coating is provided not only with the original first and second layers, but also with a fourth layer formed as an outer layer and immediately adjacent to the first layer, which itself already contributes to corrosion protection. . However, preferably such a layer structure is used as an intermediate product for the preparation of the coating and has been modified, for example by heat treatment, by at least partially integrating the original first and fourth layers. The first layer is formed including both tin and zinc. In particular, tin-containing alloys and zinc-containing alloys may be formed by such integration.

  When a fourth layer is additionally provided in the first and second layers, for a 100% by weight fourth layer, the layer is preferably at least 80% by weight zinc, more preferably at least 90% by weight zinc. Even more preferably at least 95% by weight of zinc, most preferably at least 98% by weight of zinc. Alternatively, the third layer may consist of zinc.

  The thickness of the fourth layer may be in the range of 0.1 to 3 μm, preferably 0.2 to 2 μm, more preferably 0.5 to 1.5 μm, and most preferably 0.7 to 1.3 μm. By selecting the original first and fourth layer thicknesses and the tin and zinc components formed prior to heat treatment, the tin and zinc components are adjusted to the modified first layer, which is heat treated. Is formed by at least partially integrating the original first and fourth layers.

  The layers of the aforementioned coatings may be directly adjacent to each other, according to one embodiment. However, it is possible that there may be regions between individual layers that contain one or more intermetallic compounds. Such intermetallic regions include metals from individual layers adjacent to these regions and can result from, for example, diffusion processes during prolonged storage of the coating or are specifically formed by heat treatment. obtain. For example, the intermetallic region may be between the first layer and the second layer, and / or between the second layer and the third layer, and / or between the third layer and the copper sheet, and / or the first layer. It may be provided between the first layer and the fourth layer. While not to be bound by theory, such intermetallic regions are expected to reinforce the barrier function and thus prevent the interlayer diffusion process, thereby increasing the lifetime of the coating. The thickness of the intermetallic compound region is 0.01 to 3 μm, preferably 0.1 to 2 μm, more preferably 0.25 to 1.5 μm, and most preferably 0.5 to 12 μm.

  The total thickness of the coating is from 1 to 25 μm, preferably from 2 to 20 μm, more preferably from 3 to 15 μm, most preferably from 4 to 10 μm, in particular the thickness of the individual layers mentioned above is irrelevant. Thereby, the thickness of the possible intermetallic region directly adjacent to the copper sheet takes into account the total thickness of the coating.

A further object of the present invention is a method of manufacturing an electrical terminal element, in particular a method of manufacturing an electrical terminal according to one of the aforementioned types,
Providing a substrate of an optionally hot-tin plated copper sheet;
Forming a second layer on the substrate, the second layer comprising at least a metal or at least a metal alloy, wherein the metal or metal alloy is a copper-containing alloy, nickel, palladium, and any of the aforementioned metals and metal alloys Forming a second layer selected from the group consisting of combinations;
Forming a first layer containing tin on the side of the second layer opposite the substrate.

  The shape of the substrate on which the layer is formed is not particularly limited. For example, the substrate can already have the final shape of the terminal element. In contrast, the substrate can be brought into the final shape of the terminal element only after its coating, for example by forming steps such as stamping and / or bending.

  In order not to interfere with the conductivity when in contact with the electrical terminal element, as described above, the coating is preferably formed only in the region of the substrate provided as a connecting segment. However, it is also conceivable to form a coating on other areas of the substrate, in particular the entire substrate.

  Advantageous embodiments of the method for manufacturing the terminal element are described below.

  In addition to the first layer and the second layer, optionally a third layer and / or a fourth layer may be formed as described above. Preferably, a first layer, a second layer, optionally a third layer and / or a fourth layer are formed, resulting in an arrangement of the aforementioned layers relative to each other. Thereby, the layers of the coating are preferably directly adjacent to each other and the third layer is preferably immediately adjacent to the copper sheet of the connecting segment.

  The first and second layers preferably contain the aforementioned components, particularly with respect to the individual metals or alloys used in the first and second layers and their concentrations. Also, the optional third and / or fourth layer preferably contains the aforementioned components, particularly with respect to the individual metals and their concentrations. Also preferably, the first layer, the second layer, and optionally the third layer and / or the fourth layer have a layer thickness according to the aforementioned ranges for the individual layers. Also, the total thickness of the resulting coating is preferably within the aforementioned range.

  The method for forming the layer is not particularly limited. For example, the at least one layer may be formed by a method selected from the group of electrolytic techniques, vapor deposition, sputtering, dip coating, spray coating, and any combination of these methods.

  Good results in terms of corrosion protection and coating durability include, for example, by electroplating techniques or electroplating, ie by electrolytically depositing a metal layer from an aqueous metal salt solution, the first layer, the second layer, and Optionally, it can be achieved if a fourth layer is formed. Electrolytic treatment may include further processing steps, which are commonly used in electrolysis techniques and are degreasing, cleaning and / or surface oxide removal.

  When provided, the third layer is preferably formed using dip coating. Thus, the substrate is hot dip tin plated, for example by immersing it in a hot tin bath. As mentioned above, the third layer may already be provided by using a commercially available hot-tin plated copper sheet substrate. In contrast, the third layer may be omitted, and the second layer may be formed directly on the copper sheet of the substrate.

  According to a further improvement of the method, a heat treatment is carried out after forming the layer on the substrate, assisting in the formation of intermetallic regions between the aforementioned layers. Further, as described above, the first layer and the fourth layer may be integrated to form a changed first layer by heat treatment. Such integration of the first and fourth layers utilizing heat treatment can in particular form tin-containing alloys and zinc-containing alloys.

  The heat treatment can be carried out in a temperature range of 50-350 ° C, preferably 80-300 ° C, more preferably 200-280 ° C, even more preferably 220-270 ° C, most preferably 230-250 ° C. Thereby, the temperature after the heat treatment is preferably maintained for 1 second to 48 hours, more preferably 3 seconds to 12 hours, even more preferably 5 seconds to 5 minutes, and most preferably 5 seconds to 2 minutes. . More preferably, the heat treatment is performed at a temperature between 200 and 280 ° C. and held at that temperature for a time of 5 seconds to 5 minutes. Most preferably, the heat treatment is performed at a temperature between 220-270 ° C. and held at that temperature for a time of 5 seconds to 2 minutes.

  If the manufacture of electrical terminal elements by any one of the methods described above requires formation of a substrate, the sequence of forming steps and steps for forming the coating is not particularly defined. For example, the method includes the step of stamping and bending a substrate from a copper strip to form a terminal element, wherein a layer of at least one coating is formed between stamping and bending or subsequent bending. Step may be included. It is also possible to perform a heat treatment after the layer has been formed, before or after bending.

  Another object of the present invention is an electrical terminal obtainable by one of the methods described above.

  The invention will be described with reference to the figures and with reference to possible embodiments which are merely exemplary.

It is the perspective view which showed embodiment of the electrical terminal element by this invention before connecting an electric wire. It is the perspective view which showed the terminal element shown by FIG. 1 with which the electric wire was connected. FIG. 2 schematically shows a connection segment of an electrical terminal element with a coating according to a first embodiment. FIG. 2 schematically shows a connection segment of an electrical terminal element with a coating according to a first embodiment that has been subsequently heat treated. FIG. 6 schematically shows a connection segment of an electrical terminal element with a coating according to a second embodiment. FIG. 6 schematically shows a connection segment of an electrical terminal element with a coating according to a second embodiment followed by a heat treatment. FIG. 6 schematically shows a connection segment of an electrical terminal element with a coating according to a third embodiment. FIG. 6 schematically shows a connection segment of an electrical terminal element with a coating according to a third embodiment followed by a heat treatment.

  1 and 2 show an electrical terminal element 1 having a contact portion 3 for contacting a mating terminal element and a connection segment 5 for connecting an electric wire 15. Next, the connection segment 5 is divided into a crimping part 7 having a crimping wing 9 and a holding part 11 having a holding wing 13, which are provided for fixing the electric wires 15. For this purpose, the crimping wing 9 of the crimping part 7 is crimped to the exposed conductor 17 of the electric wire 15, while the holding wing 13 of the holding part 11 is crimped to the insulator 19 of the electric wire 15. (Fig. 2).

  The connecting segment 5 is formed from a copper sheet 21 and is provided with a coating 23.

  According to embodiment 1 schematically shown in FIG. 3, the coating 23 comprises a third layer 29 of tin formed on the surface of the copper sheet 21 by hot tin plating. On the surface of the third layer on the opposite side of the copper sheet 21, a second layer 27 made of a bronze alloy containing copper, tin, and zinc is electroplated. In contrast, the second layer 27 may be formed of a brass alloy containing copper and zinc. In addition, the surface of the second layer 27 on the opposite side of the copper sheet 21 is electroplated with a first layer 25 of tin that forms an outer layer for contact with the conductor material 17. Provided (FIG. 2).

  As shown in FIG. 4, additional regions of intermetallic compounds 31, 33, and 35 are formed between layers 25, 27, and 29, and do these layers form themselves over time? Or in particular by heat treatment. In this case, the first intermetallic compound region 31 is disposed between the first layer 25 and the second layer 27, and the second intermetallic compound region 33 is disposed between the second layer 27 and the third layer 29. The third intermetallic compound region 35 is disposed between the third layer 29 and the copper sheet 21.

  FIG. 5 shows a second embodiment of a coating 23 comprising four layers. Initially, a third layer 29 of tin formed by hot tin plating is placed directly on the surface of the copper sheet 21, followed by a second layer 27 of nickel on that surface opposite the copper sheet 21. Electroplating. On the surface of the second layer 27 on the opposite side of the copper sheet 21, an electroplated first layer 25 is provided. Further, on the surface of the first layer 25 on the opposite side of the copper sheet 21, a fourth layer 37 of electrolytically plated zinc is provided so as to form an outer layer.

  FIG. 6 shows a state where the second embodiment is continuously heat-treated. By heat treatment, the originally existing tin first layer 25 and zinc fourth layer 37 were integrated into a modified first layer 39 containing both tin and zinc. The second nickel layer 27 and the third tin layer 29 are present as they are. Furthermore, the intermetallic compound region 35 exists between the third layer 29 and the copper sheet 21 by the subsequent heat treatment.

  FIG. 7 shows a coating 23 according to a third embodiment without a third layer 29 formed by hot tin plating. Rather, the electroplating layer 27 of a bronze alloy containing copper, tin, and zinc is directly provided on the surface of the copper sheet 21. On the surface of the second layer 27 on the opposite side of the copper sheet 21, a tin first layer 25 is subsequently electroplated. Further, on the surface of the first layer 25 on the opposite side of the copper sheet 21, a fourth layer 37 of electrolytically plated zinc is provided to form an outer layer.

  FIG. 8 shows a state where the third embodiment is continuously heat-treated. By heat treatment, the original first layer 25 and the original fourth layer 37 were integrated into the modified first layer 39 containing tin and zinc. Further, a second layer of bronze alloy, a modified intermetallic compound region 31 between the first layer 39 and the second layer 27, and another intermetallic compound region between the second layer 27 and the copper sheet 21. 41 is provided.

  In the following, the manufacture of the aforementioned embodiment of the terminal element 1 is described.

First embodiment (FIG. 3)
A copper strip provided with a preform having a hot-dip tin plating (third layer 29) punched from the copper sheet 21 may be formed into the shape of the electrical terminal element 1 by bending, which is initially prior to galvanization. And pre-processed. For this purpose, the preform part in which the connection segment 5 is formed is subsequently degreased at high temperature, washed, electrolytically degreased, washed, surface oxides removed and washed again. A bronze alloy is then electrically formed by electroplating as a second layer 27 on the pre-processed connection segment 5 of the aforementioned hot tin plated preform, the electroplating being 14 g / L. Run at 60 ° C. for 4 minutes in an aqueous bath having a copper ion concentration of 20 g / L and a zinc ion concentration of 4 g / L and a current density of 1 A / dm 2 (eg BRONZEX (registered by Enthone) Trademark) and WJ-SP). In this way, a second layer 27 of bronze alloy is obtained, which has 50-55 wt.% Copper, 28-32 wt.% Tin, 15-19 wt.% Zinc, and its thickness is 1 μm.

  In contrast, instead of the second layer 27 of bronze alloy, a second layer 27 made of brass alloy is obtained by electroplating the hot tin plating onto the pre-processed connection segment 5 of the preform formed. The electroplating may be performed electrically, and the electroplating is performed at 50 ° C. for 8 minutes in an aqueous bath having a copper ion concentration of 18 g / L and a zinc ion concentration of 21 g / L, and 0.5 A / dm 2 Current density (eg, using TRIUMPF 10 from Enthone). In this way, a second layer 27 of brass alloy is obtained, the thickness of which is 1 μm.

  Subsequently, before the first layer 25 of tin is electrically formed by electroplating on the second layer 27, the preform portion having the second layer 27 is cleaned and the surface oxide is removed. , Washed again. In practice, this tin plating is performed for 11 minutes at room temperature in an aqueous bath having a tin ion concentration of 80 g / L and has a current density of 1 A / dm 2 (eg non-fluoroborate non-bright tin electrolyte from Enthone) BSTANONOSTAR®, which uses HMM 2 LF). Thus, the obtained first tin layer 25 has a thickness of 5 μm.

  After tin plating, the preform is washed again and dried at 40 ° C. for 3 minutes. For the completion of the electrical terminal element 1, the preform is separated from the copper strip by stamping and is brought to its final shape by bending.

  Therefore, the obtained terminal element 1 can be connected to the electric wire 15 here by crimping.

  Optionally, the terminal element 1 may be pre-heated, in which the terminal element 1 is heated at 240 ° C. for 2 minutes and held at this temperature for 1 minute before being cooled again to room temperature. By the heat treatment, the intermetallic compound region 31 between the first layer 25 of tin and the second layer 27 of bronze or brass, and the intermetallic compound between the second layer 27 and the molten tin plating (third layer 29). A region 33 and an intermetallic compound region 35 between the molten tin plating 29 and the copper sheet 21 are clearly formed (FIG. 4).

Second Embodiment (FIG. 5)
A copper strip provided with a preform having a hot-dip tin plating (third layer 29) punched from the copper sheet 21 may be formed into the shape of the electrical terminal element 1 by bending, which is initially prior to galvanization. And pre-processed. For this purpose, those preforms that have formed the connecting segments 5 are subsequently hot degreased, washed, electrolytically degreased, washed, surface oxides removed and washed again. A nickel layer is then electrically formed by electroplating as a second layer 27 on the pre-processed connection segment 5 of the previously described hot tin plated preform, the electroplating being 113 g / L. For 7 minutes at 60 ° C. in an aqueous bath having a nickel ion concentration of 1 A / dm 2 (eg, using LETHRO-NIC®, 10-03 HSX from Enthone). In this way, a second layer 27 of nickel is obtained, the thickness of which is 1 μm.

  Subsequently, before the first layer 25 of tin is electrically formed by electroplating on the second layer 27, the preform portion having the second layer 27 is cleaned and the surface oxide is removed. , Washed again. In practice, this tin plating is performed for 11 minutes at room temperature in an aqueous bath having a tin ion concentration of 80 g / L and has a current density of 1 A / dm 2 (eg non-fluoroborate non-bright tin electrolyte from Enthone) BSTANONOSTAR®, which uses HMM 2 LF). Thus, the resulting tin first layer 25 is 5 μm thick.

  After tin plating, the preform portion with the first layer 25 is cleaned and surface oxides before the fourth layer 37 of zinc is electrically formed by electroplating on the first layer 25. Is removed and washed again. In practice, this galvanization is carried out for 3 minutes at room temperature in an aqueous solution bath having a zinc ion concentration of 160 g / L and has a current density of 1.5 A / dm 2 (eg ENTHOBRITE, an acidic zinc electrolyte from Enthone). Use). Thereby, the obtained fourth layer 37 of zinc has a thickness of 1 μm.

  After galvanization, the preform is washed again and dried at 40 ° C. for 3 minutes. For the completion of the electrical terminal element 1, the preform is separated from the copper strip by stamping and is brought to its final shape by bending.

  Optionally, the terminal element 1 may be heat treated before being connected to the wire by crimping, in which the terminal element 1 is heated at 240 ° C. for 2 minutes and again before being cooled to room temperature. Hold at temperature for 1 minute. By the heat treatment, the original first layer 25 and the original fourth layer 37 are integrated into the changed first layer 39, and an intermetallic compound region between the hot tin plating (third layer 29) and the copper sheet 21 is obtained. 35 is clearly formed (FIG. 6).

Third embodiment (FIG. 7)
The copper strip with the preform without the hot tin plating punched out of the copper sheet 21 may be formed into the shape of the electrical terminal element 1 by bending, which is initially pretreated prior to galvanization. . For this purpose, the preform part in which the connection segment 5 is formed is subsequently degreased at high temperature, washed, electrolytically degreased, washed, surface oxides removed and washed again. A bronze alloy is then electrically formed on the pretreated copper sheet 21 of the preform connection segment 5 by electroplating as a second layer 27, the electroplating comprising 14 g / L of copper ions. Run at 60 ° C. for 4 minutes in an aqueous bath having a concentration, a tin ion concentration of 20 g / L, and a zinc ion concentration of 4 g / L, with a current density of 1 A / dm 2 (eg BRONZEX® from Enthone, WJ-SP is used). In this way, a second layer 27 of bronze alloy is obtained, which has 50-55 wt.% Copper, 28-32 wt.% Tin, 15-19 wt.% Zinc, and its thickness is 1 μm.

  Subsequently, before the first layer 25 of tin is electrically formed by electroplating on the second layer 27, the preform portion having the second layer 27 is cleaned and the surface oxide is removed. , Washed again. In practice, this tin plating is performed for 11 minutes at room temperature in an aqueous bath having a tin ion concentration of 80 g / L and has a current density of 1 A / dm 2 (eg non-fluoroborate non-bright tin electrolyte from Enthone) BSTANONOSTAR®, which uses HMM 2 LF). Thus, the obtained first tin layer 25 has a thickness of 5 μm.

  After the tin plating, before the fourth layer 37 of zinc is electrically formed by electroplating on the first layer 25, the preform part having the first layer 25 is cleaned to remove the surface oxide. Removed and washed again. In practice, this galvanization is carried out for 3 minutes at room temperature in an aqueous solution bath having a zinc ion concentration of 160 g / L and has a current density of 1.5 A / dm 2 (eg ENTHOBRITE, an acidic zinc electrolyte from Enthone). Use). Thereby, the obtained fourth layer 37 of zinc has a thickness of 1 μm.

  After galvanization, the preform is washed again and dried at 40 ° C. for 3 minutes. For the completion of the electrical terminal element 1, the preform is separated from the copper strip by stamping and is brought to its final shape by bending.

  Optionally, the terminal element 1 may be heat treated before being connected to the wire 15 by crimping, in which the terminal element 1 is heated at 240 ° C. for 2 minutes and again cooled to room temperature. Hold at this temperature for 1 minute. By the heat treatment, the original first layer 25 and the original fourth layer 37 are integrated into the changed first layer 39, and the intermetallic compound region 31 between the changed first layer 39 and the second layer 27. And the intermetallic compound area | region 41 between the 2nd layer 27 and the copper sheet 21 is formed clearly (FIG. 8).

DESCRIPTION OF SYMBOLS 1 ... Terminal element 3 ... Contact part 5 ... Connection segment 7 ... Crimp part 9 ... Crimp wing 11 ... Holding part 13 ... Holding wing 15 ... Electric wire 17 ... Conductor material 19 ... insulator 21 ... copper sheet 23 ... coating 25 ... first layer 27 ... second layer 29 ... third layer 31 ... intermetallic compound region 33 ... Intermetallic compound region 35 ... Intermetallic compound region 37 ... Fourth layer 39 ... Modified first layer 41 ... Intermetallic compound region

Claims (10)

An electrical terminal element (1) comprising a connection segment (5) formed from a copper sheet (21) and provided with a coating (23), the coating (23) comprising:
A first layer (25, 39) comprising at least 60% by weight of tin;
A second layer (27) disposed between the first layer (25) and the copper sheet (21) and containing a copper-containing alloy;
The copper-containing alloy includes 40 to 80% by weight of copper and 20 to 60% by weight of zinc, and the sum of the copper and zinc is at least 90% by weight. ).   The electrical terminal element (1) according to claim 1, characterized in that the second layer (27) has a thickness of 0.5 to 5 m.   The electrical terminal element (1) according to claim 1 or 2, characterized in that the second layer (27) is made of the copper-containing alloy.   Electrical terminal element (1) according to any one of claims 1 to 3, characterized in that the first layer has a thickness in the range of 1 to 15 m.   5. The electrical terminal element (1) according to claim 1, wherein the first layer (25, 39) contains 0 to 40% by weight of zinc.   6. The coating according to claim 1, wherein the coating comprises a third layer (29) disposed between the second layer (27) and the copper sheet (21) and containing tin. Electrical terminal element (1) according to any one of the preceding claims.   The coating comprises a fourth layer (37) comprising zinc disposed on the side of the first layer (25) opposite the second layer (27). Electrical terminal element (1) as described in any one of -6. A method for producing an electrical terminal element (19) with a coating (23) according to any one of claims 1 to 7, comprising:
Providing a substrate of an optionally hot-tin plated copper sheet (21);
Forming a second layer (27) on the substrate, wherein the second layer (27) comprises a copper-containing alloy, the copper-containing alloy comprising 40-80 wt% copper and 20-60 Forming a second layer comprising: wt% zinc; and the sum of the copper and zinc is at least 90 wt%;
Forming a first layer (25) containing at least 60% by weight of tin on the second layer side opposite the substrate.   9. Method according to claim 8, characterized in that a heat treatment is performed after forming the layer (25, 27, 37).   The layers (25, 27, 37) are each formed by a method selected from the group of electrolytic plating techniques, vapor deposition, sputtering, dip coating, spray coating, and any combination of these methods. The method according to claim 8 or 9.

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